A professor thinks of two consecutive numbers between 1 and 10.
'A' knows the 1st number and 'B' knows the second number

A: I do not know your number.
B: Nor do I know your number.
A: Now I know.

What are the four solutions for this?

I am an odd number. Take away a letter and I become even. What number am I?

How many pluses should we put between the digits of 987654321 to get a total of 99, and where?

What's a single-digit number with no value?

On a bus, there is a 26-year-old pregnant lady.
A 30-year-old policeman.
A 52-year-old random woman.
And the 65-year-old driver.

Who is the youngest?

Move three sticks of the spiral below to form a square.

I taste better than I can smell. Who am I?

A swan sits at the center of a perfectly circular lake. At an edge of the lake stands a ravenous monster waiting to devour the swan. The monster can not enter the water, but it will run around the circumference of the lake to try to catch the swan as soon as it reaches the shore. The monster moves at 4 times the speed of the swan, and it will always move in the direction along the shore that brings it closer to the swan the quickest. Both the swan and the the monster can change directions in an instant.
The swan knows that if it can reach the lake's shore without the monster right on top of it, it can instantly escape into the surrounding forest.

How can the swan successfully escape?

It has a long neck, A name of a bird, Feeds on cargo of ships, It's not alive,

What is it?

When I got four, I have it none.
When I got two, I have it some.
When I got none, I have it all.

What is it?